Critically Endangered Giant Fish on Menu at Luxury Restaurants

Vietnamese restaurateurs are illegally sourcing rare Mekong River megafish from Cambodian fishermen.

Photograph by Linh Pham, National Geographic
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Phoen Sok Phoen, a fisherman who caught 250-plus-pound giant barb in his net on two separate occasions last year but called the fisheries officials to released the fish, drives his boat back home through Kompong Loung floating viallage on Tonlé Sap Lake, Cambodia. It was the first time in 10 years of fishing the Tonle Sap Lake that he’d caught one giant barb, let alone two. “I was very surprised and very afraid, because giant barb is like a god or spirit,” he says. “I prayed to it, ‘Please don’t harm me!’”
Photograph by Linh Pham, National Geographic

From the outside Nha Hang Lang Nghe, in Danang, looks like any other respectable restaurant in Vietnam. Tables are invitingly laid out in the shade of a lush garden, and festive traditional art lines attractive brick walls. Families laugh over hot pots, and businessmen clink glasses.

Yet the veneer of wholesome normality masks a dark truth: Critically endangered giant river fish are Lang Nghe’s signature dish. Although it’s illegal to sell them in Vietnam, signs at the entryway entice diners with photos of imperiled Mekong giant catfish (“tasty meat, rich in omega-3”) and giant barbs (“good for men”), while a video showing a 436-pound giant catfish being cooked and eaten plays on a screen inside. Advertisements on social media likewise boast of the delightful flavor of the enormous fish, and of their rarity.

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A 300-pound giant Mekong catfish illegally caught in Cambodia's Tonle Sap Lake is displayed at a restaurant in Hanoi, Vietnam. The fish was served to customers celebrating the 2018 Lunar New Year. The restaurant owner said that getting the “rare and special” fish from Cambodia was a challenge but that “we try our best to serve our beloved clients."

Lang Nghe is part of a growing trend of restaurants across Vietnam that are aggressively cultivating a new, dangerous market for megafish. The species they offer are so rare that the removal of even a few individuals—up to six a month in the case of Lang Nghe—may tip the animals toward extinction. But because wild freshwater fish don’t attract the same attention as tigers, elephants, rhinos, or pangolins, very few people know they’re being targeted—and even fewer are doing anything to stop it.

“The new trade seems to be very pervasive and growing very rapidly,” said Zeb Hogan, a National Geographic explorer and biologist at the University of Nevada, Reno, who’s an expert on the giant fish of the Mekong River system. “It needs to be dealt with if these species are going to survive.”

Hogan first learned that the species he studies—mainly the Mekong giant catfish and the giant barb—are being eaten in Vietnam when someone sent him a link to a restaurant’s Facebook post about a year ago. He quickly uncovered dozens of similar ads and related Vietnamese media stories. “Seeing pictures of the fish, I didn’t think the largest and most endangered ones could be coming from the aquaculture industry,” he said. “They were much too big. It looked like they must be coming from the wild.”

Although restaurant staff and media stories sometimes say the giant fish come from Thailand and Laos, the bulk of them seem to originate in Cambodia.

Trading Mekong giant catfish and giant barbs violates both international and domestic law in Cambodia. That’s also the case in Vietnam, where several species of megafish, including giant catfish and giant barbs, have been protected since 2008. While Cambodia’s current penal code doesn’t specify a punishment for poaching protected fish, in Vietnam maximum penalties for exploiting those species can result in fines of $88,000 for individuals or $658,000 for businesses, and 15 years in jail. Yet enforcement is weak: No documented evidence exists of any giant fish having been so much as seized from Vietnamese restaurants openly selling them.

Alarmed by the trend, Hogan got in touch with illegal wildlife trade researchers and activists in the region. But no one seemed to have any idea what he was talking about. All were focused on terrestrial or marine species. “Freshwater fish aren’t a priority in wildlife conservation circles,” Hogan said. “They’re hard to study, not much is known about them, and there’s not as much public empathy and support.”

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Workers collect fish at a port on Cambodia's National Highway 5, one of the main suppliers for Phnom Penh and surrounds. The Mekong River, one of the most biodiverse in the world, supports the livelihood of millions of people. Locals complain that catches are shrinking and that the river's giant fish have become exceedingly rare.

Hogan is a scientist, not a wildlife trade investigator, but in January 2018 he and National Geographic set out to search for answers to basic questions about the trade: Why are these fish now appearing in restaurants in Vietnam? Where are they coming from? Finding that out is a crucial piece of the puzzle for stopping the trade.

Monsters have long lived in the Mekong, one of the world’s most biodiverse rivers. Starting in the Tibetan Plateau and meandering through Myanmar, Laos, Thailand, Cambodia, and Vietnam, its 2,600-mile-long, latte-brown vein conceals a fantastical array of nearly a thousand fishes, many found nowhere else. Thanks to the river’s enormity and productivity, about a dozen of them grow to record proportions.

“These are some of the largest, most extraordinary, and iconic fish in the world,” Hogan said. “They’re big enough to strike even the most experienced fishermen with awe.”

Monsters of the Mekong

The 2,600-mile-long Mekong River is one of the world’s most biodiverse waterways. This rich ecosystem, home to more than a thousand species of fish, is a vital source of food and income for tens of millions of people who depend on the Mekong for their livelihood.

Mekong River Basin

Asia

Mekong River Basin

Bhutan

India

China

Bangladesh

China

Myanmar

(Burma)

Myanmar

(Burma)

Laos

Hanoi

Laos

Nay Pyi Taw

Vientiane

Thailand

Yangon

(Rangoon)

Thailand

Cambodia

Bangkok

Tonle

Sap

Ho Chi

Minh City

Cambodia

Andaman

Sea

Phnom Penh

Ho Chi Minh City (Saigon)

Gulf of Thailand

South China Sea

150 mi

150 km

Although it's illegal to export or import many species of giant fish, these protected animals are regularly trafficked between countries.

River Giants

Human shown

for scale

Mekong giant catfish

(Pangasianodon gigas)

Status: Critically endangered

Length: up to 10 ft

Giant freshwater stingray

(Urogymnus polylepis)

Endangered

16 ft 5 in (from tip to tail)

Giant barb

(Catlocarpio siamensis)

Critically endangered

10 ft

CLARE TRAINOR, NG STAFF

SOURCES: FAO, IUCN, WWF

Monsters of the Mekong

The 2,600-mile-long Mekong River is one of the world’s most biodiverse waterways. This rich ecosystem, home to more than a thousand species of fish, is a vital source of food and income for tens of millions of people who depend on the Mekong for their livelihood.

Mekong River Basin

Plateau of Tibet

Asia

Mekong River Basin

Nepal

Bhutan

India

China

Bangladesh

Vietnam

Myanmar

(Burma)

Hanoi

Laos

Nay Pyi Taw

Although it's illegal to export or import many species of giant fish, these protected animals are regularly trafficked between countries.

Hainan

Vientiane

Yangon

(Rangoon)

Da Nang

Thailand

Bangkok

Tonle

Sap

Cambodia

Ho Chi

Minh City

Human shown for scale

River Giants

Andaman

Sea

Phnom

Penh

Mekong giant catfish

(Pangasianodon gigas)

 

Gulf of Thailand

Ho Chi Minh City (Saigon)

Status: Critically endangered

Length: up to 10 ft

South China Sea

Giant freshwater stingray

(Urogymnus polylepis)

Endangered

16 ft 5 in (from tip to tail)

Giant barb

(Catlocarpio siamensis)

Critically endangered

10 ft

100 mi

CLARE TRAINOR, NG STAFF

SOURCES: FAO, IUCN, WWF

100 km

There’s the 500-pound giant freshwater stingray—a brown behemoth that glides through the water like a flying saucer—along with the giant devil catfish, a predatory species that looks like a mix between a shark and an alligator. There’s the giant salmon carp, whose perpetually downturned mouth would give Grumpy Cat a run for her money. And the giant barb, a blimp with thick, blubbery lips and scales the size of your palm, sometimes referred to as the 600-pound goldfish. Best known of all, though, is the Mekong giant catfish. Growing up to 10 feet long and 650 pounds, it’s regarded throughout the region as the king of fish.

More than just throwbacks to a wilder, more awe-inspiring time, the giants—as the rarest of the rare—in Cambodia and Laos indicate by their presence that the Mekong River ecosystem, while overfished and degraded in parts, is still functioning well enough to sustain all those less threatened species as well. Protecting the giants means protecting a living Mekong, and everything in it.

Hogan has been studying Southeast Asia’s endangered giant fish since 1997. Because giant catfish and giant barbs are so elusive, in 2000 he began networking with local fishermen and encouraging them to call his partners at Cambodia’s Fisheries Administration whenever they unintentionally caught a giant fish. The researchers would then rush to the scene to measure the fish, tag it, and release it, and the fisherman would get a small payment (not to mention bragging rights) for helping.

For years the system worked well: The fish hot line received up to 10 calls a year, and tagged fish began turning up in locations hundreds of miles apart, allowing Hogan and his colleagues to track their movement and growth. But during the past five years or so, the calls have diminished to just one or two a year—or sometimes none at all.

Scarcity Fuels Demand

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Fishermen load their catch at a dealer’s boathouse in Kompong Luong, on the Tonle Sap Lake. Cambodian dealers have traditionally avoided giant fish, thought to bring bad luck. Vietnamese dealers have no such qualms.

In Vietnam’s stretch of the Mekong, giant fish were imperiled well before Vietnamese restaurant owners sniffed them out, thanks to a mix of overfishing, pollution, and building of dams, which block essential migratory routes and change the river’s natural dynamics. There, the creatures now seem to be little more than the ghosts of old-timers’ monster tales.

“Even though the International Union for Conservation of Nature says we should protect giant catfish and giant barbs, every time people caught them in Vietnam, they were eaten,” said Mai Dinh Yen, a retired ichthyologist from Hanoi National University. “There has never been a case in which these fish were caught and then released back into the river.”

Yet it’s precisely the fact that the fish are almost gone that certain diners covet. In Vietnam, to be able to obtain and afford something scarce—even if, and sometimes especially if, it’s against the law—is a mark of one’s importance, wealth, and power. This mind-set is a major influence behind the sale of illicit wildlife goods like pangolin meat, rhino horn, ivory, and tiger parts, and it seems to be playing a role in the trade of megafish too. Their flesh has been described in the Vietnamese media as having the ability to bring good luck and boost sexual performance.

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In the past, many fishermen in Kompong Luong unintentionally caught giant Mekong fish. They hardly ever do these days.

“Vietnamese people have a saying that the bigger the fish is, the better it tastes,” said Hoang Trong Nghia, manager of Nha Hang Ngu Quan, a restaurant in Hanoi that specializes in the giants. He texts a growing pool of regulars every time one arrives. “Some people even buy giant fish as a gift for a business colleague or for a big family party because it’s so rare,” he explained. “It’s not a common gift, so it’s more special.”

Prices vary by species and size, Nghia said, with giant barbs weighing more than 220 pounds fetching the most—about $80 a pound. “Giant barb is the most expensive because it’s so rare and the quality is so great. Sometimes we even have to bid with other restaurants for it.” The largest fish he ever received, however, was a Mekong giant catfish, caught in Cambodia in December 2016 and weighing 617 pounds. “It looked like a buffalo,” Nghia said.

National Geographic explorer Zeb Hogan helps release a rare monster catfish in the Mekong River near Phnom Penh, Cambodia.


Fish like that can’t be ordered in advance because they’re so rare, he added—and they must be caught in the wild. This isn’t just a practical consideration: Wildness, like rarity, is a highly valued attribute in Vietnam.

All four restaurants I visited in the country assured me that their giant fish come from the wild. But when I spoke on the phone with Ly Nhat Hieu—who owns Hang Duong Quan, a multibranch Ho Chi Minh City restaurant that specializes in “terrible fish” and boasts a celebrity and VIP clientele—he denied that claim. “I just buy the fish from the market,” he said. “There are many, many fish farms in Vietnam now where people can grow these fish. It’s nothing special, and it’s not the natural fish.”

This runs counter to what’s reported in media stories about Hieu’s restaurant, even including posts on his restaurant’s own website, all of which state that Hang Duong Quan’s fish come from the wild—and his restaurant staff say so too. “The owner even has relatives in Cambodia to find and source the fish for him,” said a waiter at the restaurant, whom National Geographic is not naming to protect his job. “He has a lot of connections in that area, so we have giant fish all the time.” Hang Duong Quan’s largest fish, imported in late 2017, was a 6.5-foot-long, 550-pound giant catfish—a fish, according to the waiter, that “can only live in the Mekong River in Cambodia.”

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A statue of a giant barb crowns the entrance of a village near the Cambodian Fisheries Administration’s Bati field station, two hours southeast of Phnom Penh. Giant fish have long been respected—even revered—in Cambodia.

Thomas Raynaud, aquaculture director at Neovia Vietnam, a French company specializing in livestock and aquaculture management and health, agreed that such a massive fish almost certainly comes from the wild. Mekong giant catfish aren’t farmed in Vietnam, he said, and while there is some farming of giant barbs, their maximum weight seldom exceeds 20 pounds, and production is very low. Farming these species to gigantic proportions would take many years of effort and “is not realistic,” Raynaud said.

Nor are aquaculture-grown giants likely to be imported from other countries. Thailand has a number of well-established Mekong giant catfish farms, but those fish normally weigh no more than about a hundred pounds when sold.

“I’ve never heard of a pond that raised Mekong giant catfish that can grow to 300 pounds or more,” said Naruepon Sukumasavin, director of the administrative division of the Mekong River Commission in Vientiane, the capital of Laos. Some Mekong giant catfish, he added, do grow to nearly 450 pounds in government-stocked reservoirs in Thailand, but he knows of no such operations in Cambodia, Vietnam, or Laos.

Giant barbs, on the other hand, are a completely different story, Sukumasavin said. Though the species has been bred in captivity for more than 40 years, those fish are almost always released into the wild—not sold for meat.

Venerated by Some, Trafficked by Others

Cambodia has long been a stronghold for giant fish, partly because of cultural veneration for them. Mekong giant catfish appear in 12th-century carvings on the Bayon temple walls near Angkor Wat, and any fish weighing more than a hundred pounds is widely regarded as having godlike qualities. Many Cambodian fishermen consider it unlucky to catch one.

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After Phan Sok Phoen caught two giant barbs, Vietnamese traders tried to persuade him to sell the fish, which would have been illegal. “Why throw out big money?” he was asked. Phoen refused, but he says other Cambodian fishermen have chosen to break the law and work with the Vietnamese.

Phan Sok Phoen, for instance, was horrified last year when he found a 250-plus-pound giant barb in his net on two separate occasions. It was the first time in 10 years of fishing in Tonle Sap Lake that he’d caught one, let alone two. “I was very surprised and very afraid, because giant barb is like a god or spirit,” he said. “I prayed to it, ‘Please don’t harm me!’”

Phoen immediately called fisheries officials at Kompong Luong village, who helped him release the fish. To mark the occasion, he lit incense and said a few prayers, imploring the fish to bless him with good fortune for returning it to the lake.

By choosing to abide by his beliefs, Phoen passed up a big payday. Vietnamese traders began showing up in his community around two years ago, he said, looking to buy giant fish from Cambodian fishermen and presumably transport them to Vietnam. Phoen heard that they bought some 10 giant barbs last year alone. After posting photos of the giant barb he caught on his Facebook wall, a Vietnamese man called him to offer $30 to $45 a pound the next time a monster turned up in his gear. A single fish, in other words, could net well over $10,000. “Why throw out big money?” the man asked Phoen.

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Cambodian fishermen put in at a dealer’s boathouse in Kompong Luong. Vietnamese middlemen may pay $10,000 for a single giant fish, an offer that can be hard to turn down.

Phoen stood his ground, saying he wasn’t interested. “If you sell giant barbs, you’ll lose a family member, lose property, get arrested—things like that,” he told me. “Maybe I’d get money, but my family would get problems.”

While some Cambodians who ensnare giant fish may be scrupulous and superstitious, others are more interested in profit—or are motivated by desperation—and with millions of nets cast in the Mekong each day, the fish run a constant risk of being caught and sold off illegally.

El Sokrey, a fisherman in Chong Koh Chrog Changvar, a Mekong houseboat community near Phnom Penh, epitomizes the circumstances that may drive Cambodian fishermen to break with tradition and law by contacting a Vietnamese trader if they find a giant fish in their net. Sokrey said his catch of smaller river fish has declined steadily since 2008, which has had a devastating effect on his family. He used to earn more than enough through fishing to support his wife and youngest daughter and to pay for new nets and boat repairs. Now he has no choice but to repair his fraying net by hand, and his family is barely getting by.

“I’m so worried about my wife and my daughter,” he said. “I’m a fisherman: I cannot go to the land to find another job.”

Last year, Sokrey netted a giant barb weighing about 90 pounds—the first and only one he’d ever seen—but it was already dead and beginning to spoil. He’d heard of Vietnamese traders but knew they preferred live ones. So he sold the fish to his normal market trader for a meager $2.20 a pound.

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Ya Hosen (right) goes fishing with his family on their boat in Chong Koh Chrog Changvar, a Mekong houseboat community near Phnom Penh. Last year he caught a giant barb weighing about 110 pounds, but it was dead. “If I’d caught it alive," he said, "I'd have tried to find a Vietnamese middleman with a high price."

Sokrey’s neighbor, Ya Hosen, also caught a giant barb around the same time. It weighed about 110 pounds and was dead too. “If I’d caught it alive, I’d have tried to find a Vietnamese middleman with a high price,” Hosen said. “But dead fish, they do not buy.” (Phan Sok Poen, however, said Tonle Sap traders will now buy dead fish, a recent development indicative of the growing demand in Vietnam.)

Like Hosen and Sokrey, most every fisherman I spoke to in Cambodia had heard of the Vietnamese traders.

“Yeah, of course Vietnamese buy big fish!” said Chaing Pheap, who has fished from her houseboat near Phnom Penh for 20 years. “They want the big ones because there’s more meat.” Pheap said Vietnamese traders began approaching her about three years ago. Two of them even gave her business cards: “Buy giant catfish and giant barbs,” says one. The other lists only a name and phone number.

When I called that number, a man answered speaking Khmer with what my interpreter said was a strong Vietnamese accent. I asked him if he was interested in giant barbs, and he said he was, quoting prices of $40 a pound for a 200-pound fish and $25 a pound for a smaller one. “Where are you now?” the man demanded in an urgent voice. “I’ll have someone come pick the fish up now.”

The man on the phone was almost certainly working for one of the restaurants in Vietnam. According to Long Quang Bui, general manager of Lang Nghe, the Danang restaurant that features giant fish on its menu, “Fishermen are our partners, and we are their partner.”

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At Lang Nghe restaurant, in Danang, Vietnam, customers eat dinner under a poster advertising 300-plus-pound giant barbs and giant catfish. Signs at the entrance entice diners with photos of imperiled giant catfish (“tasty meat, rich in omega-3”) and giant barbs, while a video showing a 436-pound giant catfish being cooked and eaten plays on a screen inside

Nghia, the manager at Ngu Quan, in Hanoi, says there are “hundreds” of fishermen looking for these giant fish. But rather than work directly with them, he works with “a number of different guys” who act as middlemen. (Middlemen serve as a bridge between rural poachers and urban sellers.)

Recently one of these middlemen, a Vietnamese from Ho Chi Minh City, brazenly contacted Chheng Phen, deputy director of Cambodia’s Fisheries Administration, asking for help finding fishermen who sell giant fish. “You found the wrong person,” Phen told the man. “I’m the one who protects these species!”

Obstacles to Stopping the Illegal Trade

Under Cambodian law, it’s illegal to export or import “all types of natural fishery products of endangered species.” Another provision specifies that endangered species are prohibited from export unless the transfer has been allowed by authorities. But traders seem to have little trouble getting protected giant fish out of the country.

Once suppliers get their hands on a fish, Bui told me, they pack it in ice to be flown, usually by Vietnam Airlines, to Danang. “In Vietnam, when you import something from another country, usually it’s not as difficult as in the U.S.,” Bui said.

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Fishermen at Chong Koh Chrog Changvar, a Mekong houseboat community near Phnom Penh, occasionally encounter or catch giant Mekong fish. Poverty is a powerful motivator: One giant fish can earn a fisherman more than an entire year’s take.

“It’s not difficult for me to get these fish to Vietnam,” added Huynh Anh, Lang Nghe’s owner and Bui’s boss. “You just need some original documents and bills.”

Nghia also confirmed that Ngu Quan mostly sends its fish to Hanoi by air, except on the few occasions when “the plane doesn’t provide permission for the fish to go into Vietnam,” in which case the suppliers bring the fish in by car.

Because Mekong giant catfish (but not giant barbs, puzzlingly) are afforded the highest level of protection by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the treaty that regulates the global wildlife trade, trading them across a border requires both an export permit issued by the country of origin and an import permit issued by authorities in the destination country. Transporting giant fish to another country without such paperwork would be in violation of the treaty, to which all five Mekong River Basin countries are signatories.

Yet the CITES trade database—a searchable collection of all international trade in CITES-listed species, which countries are supposed to update annually—lists just six Mekong giant catfish exported from Thailand since 2011, none of which went to Vietnam. According to Cambodia’s CITES authorities, the country has never issued even one export permit for that species. And Vietnam’s CITES authority has no record of any import permits for Cambodian freshwater fish.

Anh may be able to bypass the permit formalities. “I have a good relationship with people in Cambodia’s government,” he told me. “I was introduced to these giant fish by them.” When asked to elaborate, he declined to comment further. “Selling these giant fish is sensitive. Giant catfish and giant barb are on the Red List, forbidden for catching,” he said, referring to the most endangered creatures identified by the International Union for Conservation of Nature, which sets the conservation status of species.

According to Sok Rin, vice chief of fisheries at a commune on Cambodia’s Tonle Sap lake, “One hundred percent of fishermen know it’s illegal not to release a giant barb or giant catfish.” He admitted, though, that he and his colleagues don’t carry out patrols or investigations to ensure that the laws are being followed. “We just wait for fishermen to report giant fish to us,” he said. No further explanation was given.

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Thach Phanara, head of laboratories at Cambodia’s Inland Fisheries Research and Development Institute, believes that lack of motivation and weak enforcement are serious obstacles to ending the illegal trade in giant fish. “We have to push fisheries and customs officers to do their job,” he said, “not just sit in an office and leave everything up to fishermen and middlemen.”

Thach Phanara, head of laboratories at Cambodia’s Inland Fisheries Research and Development Institute, thinks lack of motivation and weak enforcement are serious obstacles to ending the illegal trade. “We have to push fisheries and customs officers to do their job—not just sit in an office and leave everything up to fishermen and middlemen,” he said. “We have to force them to carry out the rules.”

It’s much the same in Vietnam, according to Yen, the retired ichthyologist from Hanoi National University. “Vietnam is notorious for issuing many laws, but monitoring and enforcement is weak,” he said. “The laws are quite comprehensive, but the quality and effectiveness of this agency or that department just isn’t there.”

Nguyen Quoc Manh, owner of Lau Cua Song Truce Vien, a seafood restaurant in Hanoi, said that as long as profit is involved, businesses dealing in illicit wildlife products can usually avoid being shut down. “Think about ivory—even though it’s illegal, people still sell it.”

In some cases there may be genuine misunderstanding about the law. Manh said he receives the occasional Mekong giant catfish from Cambodia or Laos, which he seemed to genuinely believe is legal. “Other restaurants import illegal fish,” he told me. “My business is going well, so why would I have to do that?”

It wouldn’t be the first time that confusion has hampered compliance in Vietnam, according to Doug Hendrie, director of enforcement and investigations at the nonprofit group Education for Nature-Vietnam. “Like some other laws that are poorly enforced, there’s indeed an awareness issue, as well as a willingness to violate the law, which is not seen as backed up by enforcement,” he said. “Putting these protected fish higher on Vietnam’s priority list would benefit the species and begin the process of strengthening enforcement that is currently lacking.”

“We Have to Work Together”

Vuong Tien Manh, deputy director of Vietnam’s CITES management authority, told me that he and his colleagues became aware of the illegal trade in giant fish only this January, when National Geographic contacted his office for comment. He said they immediately began mentioning it in workshops conducted with customs officers and began discussions with the Directorate of Customs about strengthening enforcement.

“We’d like to have more workshops on identifying these fish species and raising awareness, and to strengthen information sharing between Vietnam and Cambodia,” Manh said. “But we lack the resources to do this on our own.”

Chheng Phen, of Cambodia’s Fisheries Administration, agrees: “I don’t know how to deal with this problem alone,” he said. “We have to find a way to work together.”

Biologist Zeb Hogan is taking steps toward this goal. He’s the scientific leader of Wonders of the Mekong, a collaboration between the University of Nevada Global Water Center and the Cambodian government, funded in part by USAID and aimed at maintaining a healthy Mekong River. Now that he’s figured out the basics of the illegal trade, he hopes that bringing Vietnamese and Cambodian officials and conservationists together will lead to a plan that works for everyone. “We need to do for these fish what’s already being done for other species, like rhinos and tigers,” Hogan said. “Fish are wildlife too.”

Because giant fish are so rare, it’s impossible to predict when or where one will be caught, and the fish are also easy to hide during transport. “It’s like the traders are one step ahead of us,” Phen said.

Hogan and others believe this makes reducing demand in Vietnam the most effective starting point for curbing the illegal trade. As Hoang Anh Tuan, an ichthyologist at the Vietnam National Museum of Nature, pointed out, “If consumers don’t want this species, restaurant owners will stop providing them.”

Living Treasures

Even as some people are emptying the Mekong of its giants, others are trying to restock the river. At the Cambodian Fisheries Administration’s Bati field station, two hours southeast of Phnom Penh, a row of ponds glimmers in the late morning sun. Every now and then a ripple on the surface hints at the living treasures concealed beneath the murky water: a thousand juvenile giant barbs. They’re the stars of a first-of-its-kind experiment to replenish giant fish populations in Cambodia.

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At the Cambodian Fisheries Administration’s Bati field station, researchers are raising about a thousand juvenile giant barbs in a first-of-its-kind experiment to replenish the wild population.

In July 2017 government scientists acquired about 10,000 pint-size fish that had been netted incidentally. Some were clearly giant barbs, while other fingerlings, they hoped, would turn out to be giant catfish (it’s impossible to tell catfish species apart at such a young age).

The fingerlings were taken back to the fisheries station, where they’re now growing in the safety of the ponds. After they reach around 10 to 14 ounces, they’ll be tagged and released into protected areas—locations still to be decided—with the best enforcement and monitoring.

As the fish migrate up and down the Mekong and stray into its larger tributaries, the researchers hope that fishermen who catch them will call the phone number on the tag to claim a small reward, then return the fish to the river. That would help them monitor the fish over time.

In January 2018, six months into the experiment, the pond fish were surviving at a 25 percent rate compared with an estimated one percent or less in the wild. Also in January, and to great excitement, the researchers identified their first giant catfish—a sleek silver torpedo they named Wonder.

About 250 of the giant barbs were released on July 1, Cambodia’s National Fish Day, an annual celebration to raise awareness and enthusiasm for fish conservation. As Chheng Phen, of the fisheries administration, said, “We Cambodians care very much about these fish.”

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The fisheries administration’s juvenile giant barbs are growing in these ponds at the Bati field station. When the fish reach 10 to 14 ounces, they’ll be tagged and released into protected areas in the waters of the Mekong or Tonle Sap.

According to Hogan, the fact that fishermen had netted thousands of young giant fish shows that the Mekong ecosystem hasn’t broken down. “In rivers where there’s a systemic problem, a lot of times you don’t see young fish because the adults are not able to complete their life cycle,” he said. “Because we’re still seeing young fish in the Mekong, we know there’s still some big fish out there—which means there’s still hope.”

Hogan chooses to be optimistic. “In Cambodia, despite all the challenges, people are supportive of the idea of conserving these species. These animals are part of Cambodia’s national identity, and they’re part of what makes this country special.”

Wildlife Watch is an investigative reporting project between National Geographic Society and National Geographic Partners focusing on wildlife crime and exploitation. Read more Wildlife Watch stories here, and learn more about National Geographic Society’s nonprofit mission at nationalgeographic.org. Send tips, feedback, and story ideas to ngwildlife@natgeo.com.